Communications network congestion can often cause applications, requiring a specified quality of service, to perform poorly. Information flows generated by voice or video applications typically need to be propagated through the network on a priority basis over data applications to satisfy the requirements of these applications. Delayed delivery or the uneven jittery) delivery of voice or video information can have a negative impact upon the performance of the application and can have a consequent impact upon the quality of the experience for the user of the application.
Network congestion can be alleviated by strategically adding additional hi-speed (T1) lines to a network so that there is sufficient network bandwidth at all times, especially during times of peek traffic. However, continuing to add additional hi-speed lines can be expensive. Another known prior art technique for alleviating network congestion is the application of network management policies (policing) that operate to reserve different amounts of network bandwidth for flows of different priority. In the event that the communication network includes multiple physical signal paths of varying bandwidths, management policies can be implemented that dedicate priority traffic to the signal paths with the most bandwidth or the least amount of end-to-end delay, and in the event that one signal path becomes congested, the network traffic can be redistributed to another path to relieve the congestion. Other methods for relieving network congestion rely on delaying [temporal delay] lower priority traffic for transmission over the network until such later time that the network congestion clears up. Still other methods for relieving network congestion rely on stripping certain control information from packets at an origin location and then recreating the control information at the point that the packet arrives at a destination location or at an intermediate location where the information is needed to route the packet. Network congestion can also be relieved by dynamically assigning flows onto one or more physical or logical signal lines, thus freeing up bandwidth on other signal lines for other flows during times of peak traffic. Dynamically redistributing network flows is a practical solution in the event that all or most of the traffic is able to be processed by the infrastructure devices in the traffic path. However, in the event that the network is handling traffic using different technologies and/or protocols, dynamic redistribution can be problematical or not possible.
Many mobile cellular networks employ the standards based CDMA 2000 operating specification, or derivatives thereof, to implement packet based data communication services with the capability to send voice, video, data and signaling information between mobile communication devices and radio network controllers. One early CDMA2000 based data communications scheme was 1RTT. 1RTT was developed primarily to transmit digital voice and signaling information over a duplex pair of 1.25 MHz radio channels. Mobile communication devices and communications network infrastructure was designed specifically to generate and transmit the 1RTT traffic over the network. As other applications with higher data rates, requiring higher network bandwidth were added to mobile communication devices, it became necessary to develop data communication schemes with the ability to handle the higher data rates. EVDO (Evolution Data Optimized), LTE (Long Term Evolution) and WiMax were developed in response to these new, higher data rate, bandwidth intensive applications being used. In addition to developing the newer data communication schemes, new network infrastructure, such as routers, gateways, etc., were utilized to manage the transmission of the data through the high-speed data communication networks.
Among other things the frame sizes, frame duration, data rate and channel parameters between the 1RTT and EVDO implementations of CDMA2000 are different. While the 1RTT network infrastructure devices were designed to process frames or packets of information in a variety of different formats, such as frame relay, HDLC and IP, the newer infrastructure devices, designed to process the newer, high-speed data communication schemes like EVDO are typically not configured to process the older, legacy data forms like frame relay and HDLC. As a consequence, wireless service providers typically maintain two or more separate wireless networks, a legacy network dedicated to transmitting the 1RTT traffic and another network which can be dedicated to transmitting the EVDO traffic. Such a prior art dedicated network infrastructure architecture is shown in FIG. 1A. So, in the event that a network transmitting frame relay or HDLC traffic becomes congested, one prior art solution is to add additional hi-speed lines and additional infrastructure, but the addition of such infrastructure is expensive. Another solution is to remove, transmit and then regenerate certain control information associated with the frame/packets of information. While this method does lower the bandwidth requirement needed to transmit the traffic, it increases the latency in the traffic flow due to processing the control information for removal and re-insertion. Yet another solution is to encapsulate the frame relay or HDLC traffic utilizing the Layer 2 Tunneling Protocol (L2TP). While encapsulating frame relay and HDLC traffic using the L2TP does permit the reassignment of the traffic for transmission over another network, the frame sizes of the legacy frames tend to be small and L2TP increases the size of the encapsulated frame from twenty-five to fifty percent. Such a large increase in frame size may defeat the purpose of reassigning the traffic to another network as it can result in congestion in the other network. In any event, it is not practical to dynamically reassign the older legacy formatted frames of information from a 1RTT based network to an EVDO based network, even in the event that there is available, unused bandwidth on the EVDO based network.
Therefore, in order to efficiently utilize available network bandwidth and to avoid having to add additional hi-speed lines or have to strip and then regenerate certain control information from packets as they move through the network, we discovered that it was possible to modify the legacy frame relay and HDLC frames of information so that they can be aggregated with otherwise incompatible traffic for efficient transmission over an EVDO or other hi-speed IP based network.